| Property | Address | City | Date Listed |
|---|---|---|---|
| Alden Bridge | Main Street over Iowa River | Alden | 5/15/1998 |
| Coal Bank Hill Bridge | Near Co. Rd. VV over Iowa River | Eldora City vicinity | 5/15/1998 |
| Eldora Downtown Historic District | Approximately ten blocks in downtown Eldora around the courthouse square | Eldora | 05/12/2009 |
| Iowa Falls Bridge | US 65 over Iowa River | Iowa Falls | 5/15/1998 |
| River Street Bridge | River Street over Iowa River | Iowa Falls | 5/15/1998 |
| Washington Avenue Bridge | US 20 over Iowa River | Iowa Falls | 5/15/1998 |
| Alden Public Library | 1012 Water Street | Alden | 03/17/1981 |
| Carnegie-Ellsworth Public Library | 520 Rocksylvania Ave. | Iowa Falls | 05/23/1983 |
| Edgewood School of Domestic Arts | 719 River Street | Iowa Falls | 04/19/1979 |
| Eldora Public Library | 1219 14th Ave. | Eldora | 05/23/1983 |
| Ellsworth--Jones Building | 511 Washington Ave. | Iowa Falls | 10/01/1993 |
| Estes Park Band Shell | Estes Park | Iowa Falls | 10/01/1993 |
| First Congregational Church | 1209 12th Street | Eldora | 12/04/1996 |
| First National Bank | 601 Washington Ave. | Iowa Falls | 10/01/1993 |
| Folkert Mound Group | Address Restricted | Steamboat Rock vicinity | 03/17/09 |
| Hardin County Courthouse | Edgington Ave. | Eldora | 07/02/1981 |
| Hardin County Home Historic District | 28482 County Road D41 | Eldora vicinity | 05/24/2010 |
| Honey Creek Friends' Meetinghouse | SW of New Providence | New Providence | 02/08/1980 |
| Illinois Central Combination Depot | Ackley N. of Railroad Street between State and Mitchell Sts. | Ackley | 09/06/1990 |
| Iowa Falls Union Depot | E. Rocksylvania Ave. and Depot Street | Iowa Falls | 09/06/1990 |
| McClanahan Block | 613 Washington Ave. | Iowa Falls | 10/01/1993 |
| Metropolitan Opera House | 515 Washington Street | Iowa Falls | 02/20/1975 |
| Mills Tower Historic District | E. Rocksylvania Ave. 1/3 mi. E of Freight House | Iowa Falls | 09/06/1990 |
| New Providence School Gymnasium | 106 N. Main Street | New Providence | 10/22/1996 |
| Princess--Sweet Shop | 607 Washington Ave. | Iowa Falls | 10/01/1993 |
| Sentinel Block | 702 Washington Ave. | Iowa Falls | 10/01/1993 |
| Slayton Farms--Round Barn | 20478 135th St. | Iowa Falls vicinity | 7/07/99 |
| St. Matthew's by the Bridge Episcopal Church | Jct. of Oak and Railroad Sts. | Iowa Falls | 10/01/1993 |
| Union Cemetery Gardener's Cottage | Union Cemetery | Iowa Falls | 1/24/2002 |
| US Post Office | 401 Main Street | Iowa Falls | 01/05/1994 |
| W. R. C. Hall | 710 Washington Ave. | Iowa Falls | 10/01/1993 |